Electrical connecter



Nov. 23, 1937. v J. HARDY, JR 2,100,009

y ELECTRICAL QONNECTER- Filed March 8, 1954 2 //1---Y f" l FIG. l ATTORNEYS.

Patented Nov. 23, 1937 y UNITED STATES PATENT OFFICE ELECTRICAL CONNECTER,

James J. Hardy, Jr., Cincinnati, Ohio Application March 8,

Claims. 4

My invention'relates to electrical connecters for heavy duty or home use. It is particularly well adapted for use with electric irons, toasters, coffee pots, Wale irons and the like, where ac- 5 cording to the everyday experience of housewives, the electric cords have a very short useful life. Itis a universal and deplorably bad habit, when removing an electric plug from its-socket, to pull on the plug by means of the cord. This sort of usage has the detrimental effect, -especially where the plug fits tightly in its socket, of fraying the insulation of the cord where it enters the plug, with resulting bad effects in the Way of sparking, electric shocks, and short' circuits with ltheir attendant evils of blown fuses. My novel connecter consists of a male anda female member, which may be made of any suitable material,- which cannot be disconnected by pulling on the plug or cord, and in which the tightly gripped by the plug itself when the latter is locked in position. Coupled with this is the advantage that my plug may be positively connected or disconnected by simply giving it a quarter turn.

It is an object of my invention, therefore, to provide a connecter of the type described, having 'a male member and a female member, which may be coupled together by placing the one upon the other, and giving it a` quarter turn, and which may be disconnected in like manner but which cannot be disconnected by pulling on the cord.

It is another object of my invention, to provide a connecter as described, which will grip the cord tightly at its point of entrance, when the connecter is coupled, and which .will release this grip when the connecter is uncoupled.

Further, it is an object of my invention, to provide a connecter as described, which will be Well ventilated, so. that, after hours of ironing, it will be possible to remove the connecter manually without burning ones ngers. A

It is a further object of my invention, to provide a connecter as described, which, when couprovide cord at its point of entrance into the plug, is.

1934, Serial No. 714,603

such a connecter, which can not'only be used in forthcoming devices, but which, by a slight modification, may be adapted to electric irons and the like which are now on the market, at very little expense.

Finally, it is an object of my invention to provide a connecter having Ithe above enumerated advantages, which will be neat in appearance, simple of design, low in cost, and highly eflicient in use.

'I'hese and other objects of my invention which will be pointed out hereinafter o'r will be apparent to one skilled in the art upon reading the specications, I accomplish by that certain construction and arrangement of parts, of which I. shall now describe a preferred embodiment. Reference is now made to the drawing lwhich forms a part hereof, and in Which#- Figure 1 is a sectional view of the male member.

Figure 2 is a plan view of the male member, as

viewed from'the right in Figure 1. p

Figure 3 is a sectional view of the female member.

Figure 4 is an end view of the female member as viewed from the left in Figure 3.

Figure 5 is an end' view of the female member as viewed from the right in Figure 3.

Figure 6 is a sectional view showing the male andfemale members coupled in operative connection.

Figure 'l is a detail view of one Vof the contacts of the female member.

Figure 8is a sectional view of another form of male member.

Figure 9 is an end view of the same as viewed from the right in Figure 8. l

Figure 10 is a sectional view showing minor changes of the female member necessary in order to adapt it to an existing appliance having a. conventional male member.

Briefly in the practice of my invention, I provide a male member i, which may be made of any suitable non-conductive material. This -member is roughly cylindrical in form, Aand is provided with two ears at its base, drilled as at Zfor fastening. purposes. In the center of the top of the member i is a slot 3 which iscountersunk as at Il; Thepurpose of this slot will be described later. y The cylindrical part of this member has two holes 5, which are counterbored from the rear as at 6. The conductive prongs 1, which form a drive t'within the holes 6, are tapered near` their points, and are tapped as at, 0 at their other ends to receive theterminal 55 in order to facilitate coupling.

The female member is made from several distinct parts. The part indicated generally at I2 is a. hollow shell, having the circumferential ribs I4 and the longitudinal ribs I3, and is roughly the shape of a truncated cone. The wider end of this member has an inside diameter sufficient to fit easily over the male member l, and is provided with two internal quarter threads I6 to mesh with the threads I8 on the male member I. The other two quarters ofv the circumference are of a diameter to permit the passage of the threads I0 without engagement. Near the wide end of this member and within the shell is an annular groove I1, into which the expansion ring I8 ts.

A member I9 also in the form of a truncated cone ts loosely within the member I2, and is inserted from the wide end of the latter before the expansion ring I8 is tted in place. Fastened in the center of the wide end of the member I9 is a blade 20 having a pointed end, which, when the connecter is coupled, fits within the slot 3 of the male member. On either side of this blade are holes 2l through which the tapered prongs 1 of the male member pass. The female conta 22, best shown in Figure '7, are drilled and tapered as at 23, the taper of these holes being the same as .the taper of the prongs 1. A .slot 32 is cut diametrically through these holes, so as to make them resilient in order to more perfectly grip the aforementioned prongs. A hole 33 is provided for the fastening screws 24. The member I9 is provided with appropriate recesses, in alignment with the holes 2l, i. e. diametrically opposite, and with tapped holes to accommodate the fastening screws 24. The members 22 are mounted in the member I 9 as shown in Figure 3. Conduit passages 26, cast in the member I9, lead from the two aforementioned recesses into a larger conduit 25 which ,leads to and opens into the small end of the' member I9. Two slots 21 are cut at right angles to each other in the small end of this member and intersect the conduit 25. The periphery of the small end of the member I9 is tapered to t exactly the inside of the small end of the member I2, when the former is forced toward the right as seen in Figure 3. A substantial portion of the length of the member I9 is of reduced diameter, so that when this member is assembled with the member I2, an annular space 28 is left, which serves as Ventilating space and as a heat; insulatorl for the4 member I2, so that the latter may be grasped manually after hours of ironing, without burning ones hand. 'I'he electrical connections to the male and female members are very simple, and are adequately illustrated in Figure 6.

The operation of my device is as follows: 'Ihe female member is placed over the male member in such a way that the threads I0 pass through the spaces I5 without engagement. The blade 20 is of such a length that it contacts the countersink 4 before the threads come into mating position. A turn to the left or right will align the blade 20 with the slot 4, and then by a quarterl turn in a clockwise direction, the threads I0 are caused to engage the threads I6 of the female, pulling the female toward the left as seen in Figure 6. Then the threads having come into engagement as above described, when the member I2 is drawn over the member I, the tapered tips of the prongs 1 are introduced into the tapered holes 23 because they are automatically aligned by the alignment of the blade 20 and the slot 3. When the prongs 1 have so far entered the holes 23 that the t is tight, further movement of the member I2 to the left causes the member I9 to be moved to the right relative thereto. As this takes place, the small end of the member I9 becomes wedged by the small end of the member I 2. By these means, and by reason of the slots 21, the small end of the member I 9 is contracted, thus firmly gripping the cord 29.

In uncoupling the connecter, the reverse of the above takes place. The rst turning movement causes the member I2 to move toward the right, the member I9 remaining stationary because the prongs 1 are tightly wedged in the holes 23. As soon as the member I9 abuts against the ring I8, the member I9 is thenceforward required to move with the member I2. By these means the prongs 1 are forcefully withdrawn from the holes 23. An additional purpose of the blade 20 and the slot 3, is to relieve the torsional strain on the prongs 1 during the turning of the female member.

Figure 8 shows a male member which is generally very similar to the one shown in Figure 1, except that here the body 3l of the member is made of some brittle material such as porcelain. If the threads I0 were made of porcelain, the life of the plug would be greatly diminished on account of the brittle characteristics of this material. In order to avoid breakage, therefore, the body 3l of the plug is made smooth, i. e. without threads, and the body is encased in a metallic shell 34 having the threads crimped in it. This plug may be of the same shape as the one shown in Figure 1, or it may have flat sides as shown in Figure 9. The latter shape is frequently advantageous where it is desired to place the plug on a narrow base, as in the caseof an electric iron. In either case, however, the upper circumference of the shell 34 is crimped inwardly to grip the chamfered upper circumference of the porcelain body. The shell is provided with thesame fastening holes 2, and the body 3I and the prongs 1 are otherwise of exactly the same construction as in the plug shown in Figure 1.

Figure 10 shows how my novel plug may be adapted to a toaster, iron, or other .electrical appliance 39, which is provided with the conventional prongs 1 mounted in an ordinary base 35. All that is necessary to convert this plug so that it may be used in conjunction with a female member according to my invention, and having all the advantages above described, is to fasten onto the appliance the rnember. or members 35, halting the internal quarter threads 31. The threads 31 may be borne by a flanged tube, or, if desired, each quarter thread may be borne individually by. a member 35. The only modification necessary in the female member, is that the female quarter threads I5 are cut on the outside of the member I2 instead of on the inside.

It is to be understood that any materials mentioned hereinabove, have only been chosen Afor purposes of illustration, and are not to be deemed limitations upon my invention, and that different forms of my preferred embodiment may be made without departing from the spirit of my invention, the essentials-of which are set forth in the claims that follow.

Having now fully described my invention. what Iclaim as new, and desireto secure byLetters Patent, is: Y

l. An electric connecter comprising male and female members, one of said members having an external segmental thread and the other having an internal segmental thread, one of said members carrying a taperedinner contact carrying member having limited sliding, and free rotational movement within it.

2. In an electric connecter comprising male and female members, the fem e member being roughly of hollow frustro-conical shape and carrying at its large end an internal segmental thread, the male member carrying an external segmental thread to mate therewith, a contact carrying member of similar shape free to rotate within said female member and limited in its longitudinal motion in the direction of the large end by a retaining ring. and limited in its motion longitudinally in the other direction by the wedging action between the external andl internal conical surfaces of the small ends of the members.

. 3. In an electric connecter comprising male Aand female members, the female member beingroughly of hollow fnistro-conical shape. a con- .ftact carrying member of similar shape bored lonf gitudinally to provide a conduit for the electrical conductors and having its small end split longitudinally, rotatably carried. within said female member, and limited in its longitudinal travel in the direction of' its large end by a retaining ring, and hunted in its travel in the other direction` by the wedging action between the external and internal conical surfaces of the small ends of the members, said wedgingv action reducing the bore 'of the conduit at the small end.

4. In an electric connecter comprising male and female members, the female member being roughly of hollow'frilstro-conlcal shape, a contact carrying member of similar shape bored longitudinally to provide a conduit for the electrical conductors and having its small end split longitudinally, a substantial portion of its body 'being of reduced diameter so as to provide ventition between the external and internal conical surfaces of the small ends of the members, said wedging action reducing the bore of the conduit at the small end.

5. In an electric connecter comprising male land female members, the female member being roughly of hollow frustro-conical shape, a contact carrying member of similar shape bored longitudinally to provides-a conduit for the electrical conductors and having its small end split longi- `tudlnally, rotatably carried within said female ternal conical surfaces l members, electrical conductors passing through said conduit and connected to said contacts, said wedging action reducing the bore of the conduit at the small end whereby the said conductors are firmly gripped.

6. In an electric connecter comprising male and female members. said male member carrying tapered contact prongs, and said female member carrying contact members mounted in a rotatable member therein,and having split and tapered holes to mate with the said prongs, and mating segmental threads upon said members to force the said'prongs into the said hol in coupling, and to extract the said prongs from the said holes in uncoupling.

'1. A female member for an electrical connecter, comprising an outer shell roughly of the shape of a truncated cone, a contact carrying member which is also roughly shaped like a truncated cone and which hasa limited longitudinal sliding movement within the said shell, contact members having tapered holes for the reception of maleV contacts mountednn said last mentioned member, a conductor conduit centrally and longitudinally located in said contact carrying member, the

small end of the said last mentioned member being slotted so that'the slots intersect ythe said conduit, whereby, as the said female member is forced upon a male member, the said contact carrying member is forced toward the small end of the said shell, reducing the diameter of the said conduit and thus gripping a conductor therein.

8. A female member for an electrical connecter, comprising an outer shell roughly of the shape of a truncated cone; similarly shaped inner contact carrying means having limited longitudinal and free rotational movement within said shell, said inner means having central longitudinal means for carrying and-'gripplng'a conductor substantially at its point of exit therefrom, by cooperation with said outer shell.

9. A `female member for an electrical connecter, comprising an outer shell roughly of the shape of atruncated cone; similarly shaped inner contact carrying means having limited longitudinal and i'ree rotational movement within said shell, said inner means having central longitudinal means for carrying andgripping a conductor substantially at its point of emt therefrom, by coopera-v tion with said cuter shell said female member having means for positively coupling and uncoupling a male member.

l0. An electrical appliance having a male mem-v ber for coupling with a female member Vaccording to claim 9, said male member comprising contact 'ofthesmallendsoi'thel shell affixed to said appliance, said shell positive coupling means to mate with the coupling means on said female member.

J J. HARDY, Je. 

